Generally, the fields of building and construction produce ⅓ of the amount of total pollution in Korea, and houses and office buildings constitute 25.7% (in 2000) of national energy consumption. Thus, it is important in terms of the accumulation of resources to reduce building waste with the extension of a building's lifespan through renovation of buildings and to increase the recycling of building-related materials. Now is time for innovations in architectural technology to realize the goal of a 15% reduction in greenhouse gas emissions by 2020, a reduction in the environmental load of buildings via the development of new technologies, and to increase the recycling of resources through the extension and reuse of buildings.
The greatest factor affecting the environment in the field of building and construction may be the disposal of waste. Generally, construction waste is disposed of by landfill or incineration. Waste landfills may possibly lead to the destruction of marine environments including sea areas and coastlines, as well as the ecosystems of the land such as soil, underground water, etc. in mountainous regions. In addition, it is true that a lack of waste disposal plants and limitation of throughput in waste disposal have become a serious social problem, and particularly, illegal dumping of construction waste continues. Further, waste disposal by incineration contributes to global warming by emission of CO2 and additionally negatively affects human health due to the emission of environmental pollutants such as dioxins or the like.
As basic measures to deal with this waste disposal, it is required to prevent waste discharge, and even in this case, restrict, as far as possible, the generation of waste itself. That is, in order to obtain cyclical expansion in the field of construction, there is a rising interest in the reduction, reuse, and recycling (3R) of construction waste.
As part of an effort to deal with these problems, a unit for prefabricated buildings has been developed. Such a unit for prefabricated buildings relates to a technology whereby box-type iron frames are prefabricated in a plant, and they are assembled at sites within a short period in a simplified process.
Korean Patent No. 10-0329714 discloses a box-type unit for prefabricated buildings in which a corner post of a box-type unit for a lower-stair is provided with a screw hole, into which a screw pin is screwed, thereby facilitating the centering, screw-engaging and screw-disengaging of the pin.
Korean Patent No. 10-1020213 discloses a movable prefabricated building and an assembling method thereof, in which cones, frames, outer walls, a ceiling part, and a bottom part are individually fabricated, so that they are assembled in such a manner that the cones and the frames are assembled so as to form a framework, and the bottom part, the ceiling part and the outer walls are sequentially bolted thereto, thereby constructing the interior of the prefabricated building to suit the use of the building.
However, although the conventional techniques relate to prefabrication techniques, units are prefabricated in a plant to suit the predetermined design of the building and then are assembled at sites in such a manner that basic units are only extended so that they are connected together by means of a connection as in a so-called Lego toy, thereby constructing a desired shape of a building. However, such conventional techniques have not achieved commercial success.
Particularly, since the connection (or assembly) between the basic units is not easy, it is difficult to practically apply the conventional techniques to real structures.